INTRINSICS.md

Table of contents

• Introspection
  • Sum types
  • Product types
• Assertions

Introspection

Sum types

<sum-introspect>      = "POICA_CHOICE_INTROSPECT(" <identifier> "," { <variant> }+ ")" ;

<variant-kind>        = "POICA_VARIANT_KIND(" <variant> ")" ;
<variant-name>        = "POICA_VARIANT_NAME(" <variant> ")" ;

<overload-on-variant> = "POICA_OVERLOAD_ON_VARIANT(" <identifier> "," <aux-data> "," <variant> ")" ;

<sum-introspect>

Expands to:

<variant1>
...
<variantN>

And <variant1>, ..., <variantN> will then expand according to the rules that variants expand.

<variant-kind>, <variant-name>

POICA_VARIANT_KIND expands to either POICA_VARIANT_KIND_EMPTY, POICA_VARIANT_KIND_SINGLE, or POICA_VARIANT_KIND_MANY, depending on a kind of a passed variant.

POICA_VARIANT_NAME expands to the name of a variant.

<overload-on-variant>

The order of parameters:

1. <macro-name> is a prefix of three user-provided macros.
2. Any auxiliary data.
3. A variant, depending on which, POICA_OVERLOAD_ON_VARIANT expands to invocations of different user-provided macros

variant(<variant-name>)
--->
<macro-name>VARIANT_KIND_EMPTY(aux-data, <variant-name>)

variant(<variant-name>, <type>)
--->
<macro-name>VARIANT_KIND_SINGLE(aux-data, <variant-name>, <type>)

variantMany(<variant-name>, field(<f1>, <F1>) ... field(<fm>, <Fm>))
--->
<macro-name>VARIANT_KIND_MANY(aux-data, <variant-name>, field(<f1>, <F1>) ... field(<fm>, <Fm>))

Product types

<product-introspect>        = "POICA_RECORD_INTROSPECT(" <identifier> "," { <field> }+ ")" ;

<field-type>                = "POICA_FIELD_TYPE(" <field> ")" ;
<product-field-types-seq>   = "POICA_RECORD_FIELD_TYPES_SEQ(" { <field> }+ ")" ;
<product-field-types-tuple> = "POICA_RECORD_FIELD_TYPES_TUPLE(" { <field> }+ ")" ;

<field-name>                = "POICA_FIELD_NAME(" <field> ")" ;
<product-field-names-seq>   = "POICA_RECORD_FIELD_NAMES_SEQ(" { <field> }+ ")" ;
<product-field-names-tuple> = "POICA_RECORD_FIELD_NAMES_TUPLE(" { <field> }+ ")" ;

<product-introspect>

Expands to:

<field1>
...
<fieldN>

And <field1>, ..., <fieldN> will then expand according to the rules that fields expand.

<field-type>, <field-name>

POICA_FIELD_TYPE expands to the type of a passed field, and POICA_FIELD_NAME expands to a name of a passed field.

<product-field-types-seq>, <product-field-types-tuple>

POICA_RECORD_FIELD_TYPES_SEQ expands to:

(<F1>) ... (<Fm>)

POICA_RECORD_FIELD_TYPES_TUPLE expands to:

(<F1>, ..., <Fm>)

<product-field-names-seq>, <product-field-names-tuple>

POICA_RECORD_FIELD_NAMES_SEQ expands to:

(<f1>) ... (<fm>)

POICA_RECORD_FIELD_NAMES_TUPLE expands to:

(<f1>, ..., <fm>)

Assertions

Assertions are utility macros that check input data for consistency. They expand to nothing on success and err compilation on failure. False negatives are possible.

If POICA_ENABLE_ASSERTIONS is undefined in the current TU, these assertions always expand to an empty lexeme.

POICA_ASSERT_ARE_FIELDS, POICA_ASSERT_IS_FIELD

<assert-are-fields> = "POICA_ASSERT_ARE_FIELDS(" { <field> }+ ")" ;
<assert-is-field>   = "POICA_ASSERT_IS_FIELD(" <field> ")" ;

POICA_ASSERT_ARE_VARIANTS, POICA_ASSERT_IS_VARIANT

<assert-are-variants> = "POICA_ASSERT_ARE_VARIANTS(" { <variant> }+ ")" ;
<assert-is-variant>   = "POICA_ASSERT_IS_VARIANT(" <variant> ")" ;